Photo: FabPublic domainvia Wikimedia Commons
Composite Rosinweed Plant Care
Silphium compositum Michx.
Updated · Sources · How we source care data
Silphium compositum, the kidney-leaf rosinweed, is a flowering plant in the family Asteraceae. A perennial in the Silphium genus, it has yellow flowers and is deciduous. It grows in the southeastern United States. It has divided basal leaves.
Every 7–14 days
Full sun
60–80°F
40–70%
At a glance
How do you care for Composite Rosinweed?
Water Composite Rosinweed every 7–14 days, letting the top layer of soil dry out between waterings, and give it full sun. It prefers temperatures of 60–80°F (16–27°C) and 40–70% humidity. Fertilize it every 6 months during the growing season.
What Is the Composite Rosinweed?
Composite Rosinweed (Silphium compositum) belongs to the Asteraceae family within the Silphium genus. Composite Rosinweed is also known as Kidney-leaf Rosinweed, Silphium compositum.
Composite Rosinweed displays a tall, upright perennial growth habit, reaching up to 6 ft tall with a spread of approximately 3 ft. Composite Rosinweed produces large yellow composite flowers in late summer.
Leaf size: approximately 8 inches.
How Often Should You Water a Composite Rosinweed?
Silphium compositum requires watering every 7–14 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 7–14 days
Let soil partially dry between waterings
What Light Does the Composite Rosinweed Need?
Composite Rosinweed thrives in full sun.
Light Requirement
Full sun
What Temperature and Humidity Does the Composite Rosinweed Prefer?
Silphium compositum grows best at temperatures of 60–80°F. Composite Rosinweed prefers humidity levels of 40–70%.
Temperature
60–80°F
Humidity
40–70%
What Soil Mix Works Best for a Composite Rosinweed?
Well-draining loamy soil with added compost for nutrients. Good drainage is essential for Composite Rosinweed to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Composite Rosinweed?
Feed Composite Rosinweed every 6 months during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.
Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Composite Rosinweed?
Repot every 3-4 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Composite Rosinweed?
Composite Rosinweed can be propagated through seeds, division of rhizomes. Similar propagation techniques also apply to compass plant plant care, which shares the same genus.
Is the Composite Rosinweed Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Composite Rosinweed, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Composite Rosinweed?
Composite Rosinweed is susceptible to aphids, caterpillars, spider mites. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Composite Rosinweed Need?
Composite Rosinweed grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. In cooler regions, grow Composite Rosinweed as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 13a
Keep exploring plants
Composite Rosinweed is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Silphium genus — compare its care with other Silphium species on PlantoScan.
Silphium is part of the Asteraceae plant family — browse all Asteraceae genera and species.
Composite Rosinweed thrives in bright light and direct sun — see other bright-light plants.
More Silphium Species
Other Silphium species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Silphium compositum Michx., family Asteraceae (first published in Fl. Bor.-Amer. 2: 145 (1803)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Composite Rosinweed, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Photo: Fab, Public domain, Wikimedia Commons — original.
- Hardiness zone: USDA Zone 13a, calculated from the plant's minimum temperature.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
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